Role and Responsibilities: As a Vacuum Systems Engineer in the Defectivity group, you will work closely with Veldhoven machine conditioning architects, Defectivity MDU architects and leadership to specify vacuum systems and gas flows in scanners and test rigs. Partner with hardware project teams and lead designers to ensure vacuum and gas-flow requirements are successfully integrated throughout the product development lifecycle. Lead the ASML Wilton Engineer guild for machine conditioning architecture and vacuum systems competence onsite. Translate the overall system design into a gas-flow and vacuum architecture that meets system requirements. Specify vacuum system components, standards, and procedures and ensure they are properly recorded in Technical Product Documentation (TPD). Define, model, and execute qualification tests to verify that the architecture or subsystem performs all specified functions and meets all performance and design requirements. Support resolution of particle contamination issues through analysis and specification of flushing and venting procedures. Specify pump-down and vent procedures that ensure common flow performance. Participate in design reviews for test rigs and support functional integration of architectures or subsystems. Execute design of experiments for degassing chambers and components on product and process levels. Provide surface particulate and vacuum-grade cleanliness support, hands on troubleshoot escalations, and contribute practical recommendations from analysis. Transfer vacuum systems knowledge between ASML units and frequently interact with D&E Delivery Teams, functions, competences, customer support, and research. Perform analyses and calculations to predict flow architecture or subsystem functionality, including pressure-drop budgeting, flow budgeting, humidification, and gas purity. Take direction from ASML System Architects and principal engineering mentors leading critical large-capital-equipment development efforts. Follow EHS policies and proactively identify, communicate, and mitigate safety risks. Education and Experience: Minimum education and experience expectations vary by job grade. A bachelor’s degree in a relevant technical field is required; a master’s degree or PhD is preferred depending on role scope, technical depth, and business need. JG08: BS degree in a technical field and 5+ years of thorough experience; MS or PhD preferred. Education above a BS can compensate for years of experience depending on the candidate. JG09: BS degree in a technical field and 9+ years of substantial experience; MS or PhD preferred. Education above a BS can compensate for years of experience depending on the candidate. Solid theoretical and practical experience with vacuum and gas-flow phenomena and applications, preferably in the semiconductor industry will be given priority for hire. Internal candidates familiar with Twinscan and vacuum systems ADT, vacuum systems hands-on architecture knowledge, or ASML vacuum system flow modeling will be given priority for hire. Skills: Technical and Functional Skills Vacuum systems and gas-flow architecture: Ability to specify vacuum systems, gas flows, pump-down and vent procedures, and architecture requirements for scanner and test-rig environments. Cleanliness, materials, and contamination control: Knowledge of molecular and particle cleanliness, surface particulate behavior, vacuum-grade cleanliness, materials compatibility, desorption issues, and contamination troubleshooting. Analysis, modeling, and testing: Ability to plan and execute tests and DOEs, analyze measurement results, perform pressure-drop and flow budgeting, and use evidence to make practical recommendations. Documentation and technical communication: Ability to document standards, procedures, requirements, test evidence, and component specifications in Technical Product Documentation and present findings to varied technical audiences. Preferred technical skills: Experience with particle transport in flows, rarefied gas flow, plasma physics, electrostatics, surface science, RGA or other vacuum measurement techniques, and calculations or simulations for gas-flow and particle transport. Experience using modeling or simulation tools: to predict gas flow, vacuum performance, contamination transport, or thermal-fluid behavior is highly desirable. Demonstrate : strong technical writing and communication skills. Behavioral and Leadership Skills Drives results: Translates technical goals into clear priorities and delivers committed outcomes with quality and ownership. Collaborates and communicates effectively: Works across disciplines, suppliers, and stakeholders to align expectations, resolve issues, and transfer knowledge between ASML units. Demonstrates self-awareness: Seeks and applies feedback, adapts approach, and improves collaboration in complex or ambiguous environments. Values differences: Respects and integrates diverse perspectives to strength